It is 1540 and the hottest summer of the sixteenth century. Matthew Shardlake, believing himself out of favour with Thomas Cromwell, is busy trying to maintain his legal practice and keep a low profile. But his involvement with a murder case, defending a girl accused of brutally murdering her young cousin, brings him once again into contact with the king's chief minister - and a new assignment. An official of the Court of Augmentations has discovered the secret of Greek Fire, the legendary substance by which the Byzantines destroyed the Arab navies; lost for centuries. When Shardlake is sent to recover it, he finds the official and his alchemist brother horribly murdered - the formula has disappeared.